import { useEffect, useRef } from "react";

export const useIsMounted = () => {
  const isMounted = useRef(false);
  useEffect(() => {
    isMounted.current = true;
    return () => {
      isMounted.current = false;
    };
  });
  return isMounted;
};

export const useInterval = (callback: Function, delay: number) => {
  const savedCallback = useRef<Function>();

  // Remember the latest callback.
  useEffect(() => {
    savedCallback.current = callback;
  }, [callback]);

  // Set up the interval.
  useEffect(() => {
    function tick() {
      savedCallback.current && savedCallback.current();
    }
    if (delay !== null) {
      let id = setInterval(tick, delay);
      return () => clearInterval(id);
    }
  }, [delay]);
};
